For starters, you could check out Import Export for Dummies, Export Import, Procedures and Documentation by Thomas E. Johnson & Donna L. Bade.
For resources, check out "Dictionary of International Trade" below
http://www.worldtradepress.com/Dictionary_of_International_Trade.html Note: This is not a representation of the quality of the above books, nor am I affiliated with the books in any way above.
It sounds like you are really committed to being a wholesaler.
Can I suggest that the best way for you to get the knowledge, skills, contacts and experience you are looking for is to go and work for someone for a while who is excellent at doing what you want to do.
This way, you will have an opportunity to get to know the wholesaling business and decide what area you want to be in and what you learn will be invaluable in making your business successful when you do start it. And, you'll get paid!